Revised and extended analysis of eight-times ionized cesium ion: CsIX

The ninth spectrum of cesium (Cs IX) was recorded oil various spectrographs in the 100 angstrom - 1200 angstrom region using a triggered spark source. The earlier analysis of Cs IX has been found to be mostly correct. The missing 4f(2)F levels have been found and the exact energy level values of the 5g(2)G and 6g(2)G levels have been determined. The spectrum has been considerably extended. Fifty lilies are now calssified in the Cs IX spectrum. 26 of them are newly classified lines. All levels of the its (n = 5-9). np (n = 5-8). 5d. nf (n = 4-5) and ng (n = 5-9) configurations are now known. Eleven levels (J = 1/2, 3/2) of the 4d(9)5s5p configuration and two levels 4d(9)4f5s(2)P have also been established. Energy level values of 21 levels have been reported for the first time. Hartree-Fock and least-squares-fitting calculations were carried out to interpret the reported spectrum.